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`J. H. CROSKEY 8v J. LOCKE.

-INSULATOR POR ELEGJTRIGv GONDUGTORS. No. 530,399. PatentedfDec. 4, 1894.

Cf l@ I3 UNITED STATES PATENT OFFICE'.

JOHN H. OROSKEY AND JOSEPH LOCKE, OF PITTSBURG, PENNSYLVANIA.

INSULAT'OR FOR ELECTRIC CONDUGTORS.

SPECIFICATION forming am of Letters resent No. 530,399,

dated December 4, ise4.

Application filedSeptember 2B, 1894. Serial No. 524,365.. (No model.)

To all whom it may oon/echt.'

Be it known that we, JOHN H. CROSKEY and JOSEPH LOCKE, citizens ot' the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Insulation for Electric Conductors;

arid-we do hereby declarethe following to be a full, clear, and exact description 0f the in' ventionsuch as will enable others skilled in the art to which it appertains lto make and use the same. This invention has relation to insulation for electric conductors and has for its object the provision of insulation of a. novel character, which will not only perfectly insulate the wire or other condctor vand prevent the esf cape of electricity, but will protect; the wire i from the action of the atmosphere or any 'dele-.-

-terious chemical action or physical injury.

` In carrying our invention intoeffect we coat.4 or c over the conductor, or lconductors,

`4with a non-conducting' material of high refractory or incombustible properties,` such as asbestos, and superimpose on the asbestosorsimilar material a coating of molten, glass so as to completelyinclose and 4tightlyembrace the conductor or conductors. A single conductor may be insulated in the above manner orally number of conductors maybe 'separately coated with -asbestos and carried in a. single section of glass, butkept separate and apart by the intervening glass, or the conductors may be bunchedor grouped, asl in a cable, and insulated each from the other by any suitable. substance, and the wholebunch or group coated or covered with ashes tos and then coated with glass. v

Where the conductor or conductors only require special insulation for short lengths, as for interior wiring,` or "for lightinggftelegraph, power, or similar fittings or accesso'- riesfthe glass covering may be made in a single length,l piece, or, section, but where it is desired to insulate a conductor or conductors for a considerable length such, for instance,

as underground mains, we form the conductor or conductors with our insulation in a number of lengths and, after having suitably connected the abuttingends of the conductors, as by electric welding, we ycoat the joined ends of the conductors with an insulating material and then inclesethe joint in two half-sections of glass that overlap the, adjacent ends of the glass covering et the conductors and 'thus form aV tight and secure joint at the junction ot each length.

'.Our invention consists in the improved insulation forelectricalconductors herein described and claimed.

In theiaccompany-ing.drawings Figure lis ,a vertical longitudinalsection of a compound conductor containing several strands or wires,

joined together. Fig. 2 isa vertical ltrans- `verse section of the same, Figs. 3, 4, 5, and

6 vare sectional views of various ttings or accessories used in electric lighting and power transmission, all constructed according to our invention. t

In formingtlie lengths et the compound conductorllustrated in- Fig. 1 ot the drawings, we wrap or otherwise inclosethe wires,

metallic materiali, B B, and lay the wires-flat upon a'heatedvtable or other support.` We then' pour the glass C upon the table over the wires and, by means of a suitable roller or rollers, roll and'press the molten glass upon and around vthe wires. By using a tableor support vhaving its surface grooved to coincide with spaces'between the wires the glass may be pressed between the wires andthen reversed and the projecting ridges rolled down upon and over-the wires so as to completely embed the same in a solid mass of glass..

After the wires have been inclosed in the glass as described, the several lengths are laid in a suitable trough, trench or conduit and the abutting ends'of the wires welded together,l preferably by the well known pro- 'ess of electric welding. The welded ends are then surrounded by a suitable insulating material D, which rmay be plaster of paris er other plastic, and thev joint finally inclosedin half sections of glass E E, which overlap the adjacent ends of the glass sections C C, and are'held in position bybands or' straps F F, or other suitable fastening devices.

In the manufacture of the fittings shown in Figs.' A3, 4, 5, and 6, the conductors A A-, are coated or wrapped with the asbestos B B, and then placed'in suitable molds and the glass C is pressed around the conductors,

thewhole being made up of several lengths A A, in asbestos or other refractory non- IOO s eeeeeae rmly embracing and holdingthem in posieictingofa metallic strand-covered with astion. The advantage of employing a conbestoe andembedded ie glass. ductor coated with asbestos is that the glass 3. An electrical conductor consisting of will adhere more closely and firmly to the lengths of glass having asbestos coated wires 5 asbestos than it would to the naked wire and embedded therein, the adjacent ends of the 2o there is much less liability of the glass craek- Wires being welded together and covered with ing through inequality of expansion and cone plastic non-conductor, substantialiy :1s/detraction when the glass is tiret applied and ecribed., also when, through excess of current, the Wire 1in testimony whereof wcaffix oursignatures 1o becomes heated when in use. iu presence ci two witnesses.

Havingdescribed ourinvcntion, We claiml. H. CROSKEY. 1. Aninsulated conductorof electricitycent SSEPH LOCKE. eisting of a. metallic conductor covered with Witnesses: a non-metallic mineral and embedded in glass. C. E. SUCCO?, 15, 42. An insulated electrical conductor con- JNO. M. MCDONALD. 

